Barnyardgrass shows sensitivity to reduced doses of topramezone at different growth stages

Using less than the labelled dose of herbicides depends mostly on weed spectrum and growth stage of target weeds. The aim of the greenhouse experiment was to determine the efficacy of recommended (67.2 g a.i. ha-1) and reduced doses (44.8, 33.6, 22.4, 16.8 and 8.4 g a.i. ha-1) of topramezone combined with adjuvants (NIS and MSO) on barnyardgrass (Echinochloa crus-galli [L.] P. Beauv.) at two different growth stages: BBCH 13 and BBCH 21\u201322. The results showed unsatisfactory efficacy of topramezone applied alone at the recommended dose on both growth stages (>50%). When applied with adjuvants (MSO or NIS) at BBCH 13, topramezone 100% visually damaged barnyardgrass and reduced biomass >90%, at each applied dose. In contrast, at BBCH 21\u201322 only topramezone double dose achieved 73% visual damage. Reduced topramezone doses applied with adjuvants gave insufficient barnyardgrass control at tillering stage (< 40%). Results indicate the possibility of reducing the topramezone dose to more than 87% by adding adjuvants (MSO or NIS) but only when applied at early growth stage of barnyardgrass (BBCH 13). At BBCH 21\u201322 satisfactory barnyardgrass control cannot be achieved by using topramezone either alone or with adjuvants

Brokerage as an institutional strategy in fragmented fields: the crafting of social entrepreneurship

Although the scholarship on organizational fields has prevalently focused on emerging, mature and disrupted fields, some social arenas cannot be classified in any of these categories. One such field is that of social entrepreneurship. Despite its progressive establishment and the development of shared norms, understandings, regulations and values governing all of its players, this field still presents unclear boundaries, multiple conceptions, and a high ambiguity in terms of legitimate roles, practices and organizational forms. How can this be the case? The work of some scholars shows that meso-level factors are required to explain the peculiarity of this field. This study builds on their findings and uses the social entrepreneurship field in England as setting to explore how institutional agents can favour the creation of a fragmented field and successfully operate in it. Influencing a fragmented field requires both the creation and the maintenance of a coalition of key stakeholders supporting the enactment of the desired institutional architecture over time. Therefore, this research explores what organizations do to maintain the support of multiple stakeholders in competitive settings and to use the advantages that this creates for sustaining the co-existence of their desired field’s conception and institutional architecture with competing ones. Given the advantages that brokers have in such settings and in pursuing such a strategy, this work makes use of the well-developed literature on brokerage strategies, which focuses on tertius gaudens and tertius iungens strategic orientations, and connects it with that on institutional agency. By using as case studies four brokering agencies active in the social entrepreneurship field in England, this study discovers that combinations of gaudens and iungens strategic orientations, when used by institutional agents, can help them create and sustain over time their sub-field in face of competition. Furthermore, it explores how the co-existence of multiple organizations adopting complementary brokerage strategies as institutional ones, can lead to the creation of a permanently fragmented field. Together, these findings contribute to develop the literature on brokerage, on institutional agency — especially in relation to fragmented fields —, and that on social entrepreneurship

Unpacking social entrepreneurship: exploring the definition chaos and its consequences in England

Social entrepreneurship has always been a contested concept, both within the academic discourse and in practice. A lot of scholarly effort has been put in analyzing the different definitions of social entrepreneurship and the negative consequences that the definitional debate has on the opportunity to advance social entrepreneurship as a research field. Very little is known on what are the consequences of the multiple meanings of social entrepreneurship for people working in the sector. This paper advances knowledge on this topic by looking at the social entrepreneurship sector in England and by investigating through qualitative research methods what sector members think about social entrepreneurship and its unclear boundaries. The results show that there are three different conceptions of social entrepreneurship within the sector in England. However, while everyone agrees on the presence of a definitional debate, opinions on what this means for the sector are several. Some members think it is something positive, some others think it is causing different issues and a third group considers it as irrelevant

Unpacking Social Entrepreneurship: Exploring the Definition Chaos and Its Consequences in England

Social entrepreneurship has always been a contested concept, both within the academic discourse and in practice. A lot of scholarly effort has been put into analyzing the different definitions of social entrepreneurship and the negative consequences that the definitional debate has on the opportunity to advance social entrepreneurship as a research field. Very little is known about what the consequences of the multiple meanings of social entrepreneurship are for people working in the sector. This paper advances knowledge on this topic by looking at the social entrepreneurship sector in England and by investigating through qualitative research methods what sector members think about social entrepreneurship and its unclear boundaries. The results show that there are three different conceptions of social entrepreneurship within the sector in England. However, while everyone agrees on the presence of a definitional debate, opinions on what this means for the sector are several. Some members think it is something positive; some others think it is causing different issues, and a third group considers it as irrelevant

Unpacking Social Entrepreneurship: Exploring the Definition Chaos and Its Consequences in England

Social entrepreneurship has always been a contested concept, both within the academic discourse and in practice. A lot of scholarly effort has been put into analyzing the different definitions of social entrepreneurship and the negative consequences that the definitional debate has on the opportunity to advance social entrepreneurship as a research field. Very little is known about what the consequences of the multiple meanings of social entrepreneurship are for people working in the sector. This paper advances knowledge on this topic by looking at the social entrepreneurship sector in England and by investigating through qualitative research methods what sector members think about social entrepreneurship and its unclear boundaries. The results show that there are three different conceptions of social entrepreneurship within the sector in England. However, while everyone agrees on the presence of a definitional debate, opinions on what this means for the sector are several. Some members think it is something positive; some others think it is causing different issues, and a third group considers it as irrelevant

In vitro and in vivo evaluation of T and B lymphocyte functions in AKR mice.

To investigate whether AKR spontaneous leukaemogenesis is associated with a reduction in functional activity of T lymphocytes, the PHA response of AKR blood cells at different ages up to and including the preleukaemic period was studied. No significant differences were observed among young, adult and preleukaemic donors. In addition, the in vitro and in vivo AKR lymphocyte functions were compared with those of CBA lymphocytes by means of their response to stimulation with T and B lymphocyte selective mitogens (PHA, Con A and LSP respectively), and their response to immunization with thymus dependent (SRBC) or independent (LPS) antigens. We observed in vitro that while the B lymphocytes responded normally to mitogen, an intrinsic hyporeactivity to mitogens characterizes the T lymphocytes. Moreover, AKR mice exhibited a reduced in vivo response to both thymus dependent and independent antigens

TUMOR INDUCTION BY MURINE SARCOMA VIRUS IN AKR AND C58 MICE : Reduction of Tumor Regression Associated with Appearance of Gross Leukemia Virus Pseudotypes

Adult AKR and C58 mice injected intramuscularly with murine sarcoma virus, Moloney isolate (M-MSV), developed high incidence of nonregressing local tumors. Histologically, these tumors revealed the typical pleomorphism of M-MSV sarcomas; in some cases, however, neoplastic tissue showed a nodular or diffuse growth of monomorphic myoblastlike cells, reminiscent of clonal aggregates. No depression of immune reactivity was found in M-MSV-injected mice as evaluated by direct hemolytic plaque-forming cells against SRBC and by virus-neutralizing antibody production. The MSV recovered from the induced tumors proved to be, by neutralization assay, a Gross (G)-MSV pseudotype. Moreover, tumor cell suspensions absorbed out cytotoxic antibody directed against G-cell surface antigens. Therefore, the conclusion was drawn that MSV with envelope characteristics of endogenous G leukemia virus had formed in vivo through a phenotypic mixing phenomenon. The failure of tumors to regress has been interpreted as mainly due to the partial unresponsiveness of host immune reactivity towards G-MuLV specified antigens. Since MSV-tumors arose in AKR mice after a very long latent period, the possibility was considered that this relative resistance might depend on immunologic mechanisms. In fact, M-MSV-injected AKR mice immunodepressed by goat antimouse lymphocyte serum or rendered partially tolerant by neonatal M-MuLV inoculation developed sarcomas with higher incidence and with a shorter latency. Furthermore, the MSV recovered from these early tumors proved to be the original Moloney pseudotype